Prefabricated modular panel structure and modular panel units therefor



' P 1 -c. D. SMITH ,343,314

PREFABRICATED MODULAR PANEL STRUCTURE AND MODULAR PANEL UNITS THEREFOR Filed June 15, 1965 3 Sheets-Sheet l v INVENTOR. CLOYD D. SMITH ATTORNEY Sept. 26, .19 7

. Filed June l5, 1965 CL CL ShdFTH PREFABRICATED MODULAR PANEL STRUCTURE AND MODULAR PANEL UNITS THEREFOR 5 Sheets-$heet 2 45' 88'. wih

. miummg I m 8' .n o .Z| jm 2 o 240 5 6% 95% a z g 4%o 480% I INVENTOR- REQUENCYINCYCLESPERSECOND CLOYD D SMITH ATTORNEY Filed-Jufie 15, 1965 Se t. 26,1967

C. D. SMITH PREFABRICATED MODULAR PANEL STRUCTURE AND as 70 FIG. 56 56 3 22 553? :ii'ii 52155133 52 V1! '6 n,

MODULAR PANEL- UNITS THEREFOR 3 Sheets-Sheet 5 INVENTOR. CLOYD D. SMITH ATTORNEY United States Patent 3,343,314 PREFABRICATED MODULAR PANEL STRUCTURE AND MODULAR PANEL UNITS THEREFOR Cloyd D. Smith, 14928 La Cumbra Drive, Pacific Palisades, Calif. 90272 Filed June 15, 1965, Ser. No. 464,153 6 Claims. (Cl. 52-145) This application is a continuation-in-part of my earlier copending application, Ser. No. 55,346, filed Sept. 12, 1960, entitled, Prefabricated Modular Panel Structure and Modular Panel Units Therefor, now abandoned.

This invention deals generally with prefabricated building structure for rooms or other enclosures and particularly with prefabricated soundproof modular panel units for the structure.

The invention has primary untility in the construction of acoustically insulated rooms for environmental testing and equipment testing, or for insulating a source of noise.

Certain features of the invention, however, concern the structural features of the panel and its securing arrangements, and these, of course, are useful through a wide field of applications in addition to that of acoustic insulating.

The primary general object of the invention may be said to be the provision of a room, made from prefabricated modular panels, whichis simple in construction, of relatively light weight, easy to erect at the building site, and which has, nevertheless, highly superior noise reduction characteristics.

A further object of this invention may be stated as being the provision of a new and unique prefabricated modular panel building structure and prefabricated modular panel units for the structure, which are uniquely designed for ease and quickness of assembly at the building site.

Though made inexpensively of relatively light components, a room constructed in accordance with the invention has soundproof qualities comparable to one constructed of 6" concrete Walls.

The invention will be understood from the following detailed description of certain presently preferred illustrative embodiments thereof which are illustrated in the attached drawings. In these drawings:

FIG. 1 is a perspective view, partially broken away, of a portion of one type of the present modular panel-building structure constructed from the present prefabricated modular panel units;

FIG. 2 is an enlarged section taken along line 2-2 of FIG. 1;

FIG. 3 is an enlarged section taken along line 33 on FIG. 1;

FIG. 4 is a section through two assembled, acoustic insulating modular panel units;

FIG. 5 is a section through two assembled, modified acoustic insulating panel units of the invention;

FIG. 6 is a section through two assembled, modified acoustic insulating panel units of the invention;

FIG. 7 is a section through a fragmentary modular panel unit as in FIGS. 4 to 6, but with improved acoustic insulation features;

FIG. 8 is a performance graph of the embodiment of FIG. 4;

FIG. 9 is an enlarged section through two assembled, angularly disposed modular panel units of the invention, which may be a wall panel and a ceiling panel, for example;

FIG. 10 is also an enlarged section through two assembled, angularly disposed modular panel units of the invention illustrating an alternative way of joining such panel units;

FIG. 11 is an enlarged section through two assembled panel units of the invention illustrating in enlarged detail the manner of joining adjacent panel units of the invention; and

FIG. 12 is an enlarged section through a present modular panel unit illustrating one manner of attaching the latter to the floor.

The modular unit, prefabrication features of the invention will be described first, and its unique high performance noise reduction features and qualities will be stressed thereafter.

Referring first to FIGS. 1-3 of these drawings, the present prefabricated modular panel building structure 20 illustrated therein comprises a series of vertical, prefabricated modular panel units 22, 24, 26, 28, and 30 which are assembled in the manner to be presently described to form a room or enclosure. Panels 22 are solid panels. Panel 24 is a door panel having an access opening 32 to the room closed by a hinged door 34. Panel 26 is a window panel having a window opening 36 closed by glass panes 38. Panel 28 is a ventilation panel formed with an internal ventilation duct 40. The lower end of this panel unit has a grilled opening 42 to the duct and the upper end of the unit has another opening (not shown) to the duct for connection to external ventilation equipment. Finally, panel unit 30 is a service panel whichis equipped with fluid and electrical service connections 44 which are accessible from both the inside and the outside of the panel.

These several panel units of the prefabricated building structure may have any one of the panel constructions shown in FIGS. 4-7. For convenience, however, the panel units of the building structure in FIG. 1 have been illustrated as being of the type shown in FIG. 6, soon to be described.

The modular panel unit illustrated in FIG. 6 comprises a sheet metal pan 46 having a rectangular side wall 48 and right angle flanges 50 along the two longitudinal edges of the side wall. The unit 22 comprises, in addition to this basic pan structure 46 of FIG. 6, a relatively shallow sheet metal cover pan 52. This latter pan is positioned between the flanges 50 of the pan 46 and includes a rectangular side wall 54 having flanges 56 along its longitudinal edges seating against the flanges of the basic pan. The seating flanges are spot welded or otherwiserigidly secured together. The side wall 54 of the shallow pan is disposed between and spaced from the side wall 48 of the basic pan 46, and the flanges 56 on the shallow pan extend toward and terminate substantially flush with the outer longitudinal edges of the flanges of pan 46.

Pan side Walls 48 and 54 and the pan flanges 50 define therebetween a chamber 58. Filling this chamber is a core 60 of acoustic and/or thermal insulating material such as plaster board, fiberglass, rock wool, foam, or other suitable insulating material. This core is bonded to the inner surfaces of the outer pans 46 and 52 and performs the additional function of stiffening the panel unit. In FIGS. 9 and 12, the ends of the chamber 58 in the panel unit will be seen to be closed by Wall members 62 in the forming of channels which are spot welded or otherwise rigidly joined to the walls of the panel unit. These channels open toward the ends of the panel unit, as shown.

The other panel units 24, 26, 28 and 30 in the building structure of FIG. 1 are substantially identical with the panel 22 just described, except that the former panel units have a door, window, ventilation duct, or service connections, as discussed earlier and shown in FIG. 1. All of the several different panel units in the structure of FIG. 1,.then, have in common the feature that the seating flanges 50 and 56 of the basic pans 46 and cover pans 52 of the units extend a distance beyond the side walls 52 of the respective cover pans.

When assembling the panel units 22, 24, 26, 28 and 30 of FIG. 1 to form the building structure of that figure, the units are placed side by side with adjacent flanges 50 thereof in abutment, as shown best in FIG. 11. Strips of sealing tape 64 may be placed between the abutting flanges to seal the latter to one another. A U-shaped panel joining strip 66 is then placed over the extending portions of the abutting flanges and bolts 68, inserted through aligned holes in the flanges and joining strip, clamp the adjacent units together. A U-shaped sealing strip 70 may be placed between the flanges and joining strip 66, as shown, to seal the joint between the adjacent panel units. The flanges may extend into the room, as in the building structure of FIG. 1, or the panel units may be reversed so that the flanges extend to the outside of the room.

The upper and lower edges of the panel units fit in channel members 72 which are joined to the panel units by screws 74. These channel member maintain the several panel units making up each side wall of the building structure in FIG. 1 in line. As shown best in FIG. 12, the lower channel member 72 may be bolted to the floor.

As may be observed in FIGS. 1, 9 and 10, the panel units 22 serve also as ceiling panels. The ceiling panels can be secured to the wall panels in many different ways. As shown in FIG. 9, for example, the ceiling panels can be arranged so that flanges 50, 56 in the ceiling panels adjacent the walls, extend down alongside the upper ends of the Wall panels for attachment to the wall panels by the screws 74.

In the alternative, the ceiling panels may be reversed so that their flanges 50, 56 extend upwardly and away from the wall panels as shown in FIG. 10. In this case, the longitudinal edges of the ceiling panels adjacent the wall panels may be joined to the latter by L-shaped joining strips 78 which are bolted to the ceiling and wall panels in the manner shown in FIG. 10. The joints between the ceiling and wall panels, and between the adjacent ceiling panels, may be sealed by strips of tape, as described earlier. The ends of the ceiling panels can be secured to the wall panels by an L-shaped joining strip 79 (FIG. 1) which is bolted to the ceiling and wall panels.

FIGS. 4, 5 and 7 illustrate special acoustic noise reduction modular panels which may be used when a high degree of sound attenuation is required through the walls of rooms constructed therefrom.

The acoustic panel 84 of FIG. 4 uses a pan structure 46 like that of FIG. 6, and a laminated acoustic sound absorptive core 601:. The core is made up in layers, with each layer designed for good sound absorption properties for a given range of the audio spectrum, with the assembly of layers thereon to cover the frequency spectrum to be attenuated. In the case of FIG. 4, the core comprises first, a layer 87 of relatively hard and dense acoustic attenuating material, having high acoustic transmission loss or barrier properties particularly for the low frequency range, and this layer 87 is placed adjacent and bonded to the metallic side wall 48 of the pan (which is normally the outside wall of the room, and may be referred to as the back wall). This layer 87 brackets the lower portion of the audio frequency range, say 20 cycles per second, up to approximately 250 cycles per second. This relatively dense layer may comprise a sheet of ordinary plasterboard, Masonite, or plywood. It acts in the first instance as a barrier to low frequency sound, and tends to reflect it back. What low frequency sound does penetrate the layer 87 tends to set it into vibration, and would ordinarily be radiated from its rearward side. How this sound is attenuated further by the invention will be described presently.

Next to, and bonded to, the layer 87 is a layer 88 of acoustic attenuating material suited more particularly to attenuation of the higher range of the audio spectrum, as from 200 to 6,000 cycles per second, and for this purpose I use a layer of relatively porous acoustic insulating or absorption material such as fiberglass or rock Wool.

This layer is preferably substantially thicker than the dense layer 87, as illustrated, and is bonded thereto, the same as the layer 87 is bonded to the wall 48.

Over and against the layer 88 is an acoustically transparent sheet 89, composed in this case of perforated sheet metal which readily transmits sound waves incident upon it. The sheet 89 is in this case in the nature of a sheet metal cover pan having flanges 90 along its longitudinal edges which are spot welded or otherwise firmly attached to the flanges 50 of the pan structure 46. The sheet 89 may be bonded to the layer 88, but this has not been found to be essential to obtainment of good results.

It is very important, however, that the dense layer 87 be adhesively bonded to the outside or back metal wall 48, for a reason that is not entirely evident and should be fully explained. Briefly, this bonding means that the metallic outside wall 48 is very substantially deprived of its otherwise inherent proneness to vibrate or ring in response to incident sound waves, such as sound waves radiated from a wall or layer adjacent to the wall 48, particularly when the sound has frequencies in the range of a resonant frequency or frequencies of the wall 48. Instead, the layer 87, which is substantially thicker than the sheet metal wall 48, and is bonded face-to-face to the wall 48, strongly damps the vibration of the wall 48. The action is believed to be as follows:

The sound waves in the lower frequency range are substantially stopped, i.e., reflected back, by this layer 87. Those that do penetrate and are transmitted through layer 87 would, if the layer 87 were not bonded to wall 48, be radiated to the wall 48, and would easily set it into vibration, particularly in the case of frequencies in the region of the resonant frequency of the wall 48. This vibratiton at resonance can be very substantial. With the bonding of the hard and dense layer 87 to the metal wall 48, however, an integrated structure of increased stiffness is attained whose resonant frequency is shifted from that of the metal wall to a less bothersome range. Also, acoustic damping occurs by attenuation of the sonic Wave energy through the layer 87, and this damping is enhanced by internal work done within the material of the layer 87 by the tendency for said layer to vibrate with the metal wall 48. Thus, the dense layer 87, integrated structurally to the wall 48, attenuates the vibration amplitude of the wall 48, and produces large acoustic transmission losses both through itself and through the wall 48. It is stressed that these results are attained by virtue of the bonding of the hard and dense layer 87 to the sheet metal wall 48, since it is the tendency for the wall 48 to vibrate which transversely bends the material of the layer 87 so as to produce the overall degree of attenuation obtained by this combination.

The layer 87 bonded to the wall 48 attenuates the low range of the audio acoustic spectrum better than has heretofore been obtained, to my knowledge. It is still necessary to take care of the higher ranges of the acoustic spectrum, and this is done, in the bracket from about 200 to 8,000 cycles per second, by the porous layer 88.

The porous layer 88, formed of porous, fibrous material such as rock Wool or fiberglass, and thus of lower density than the hard and dense layer 87, has acoustic absorptive properties and is dissipative of acoustic energy particularly in the bracket from 200 to 8,000 cycles. Sound waves incident on this layer 88 of absorptive material and transmitted through it tend to vibrate the indi vidual fibers of the material. By having this layer 88 bonded to the hard, dense layer 87, sound in the upper frequency bracket mentioned tends to be reflected back at the bonded interface, and the reflected waves tend to interfere with or buck the vibrations of the forwardly traveling waves. Moreover, the vibration of the hard and dense layer 87 causes vibration of the near side of the fibrous absorptive layer 88, and these vibrations and transmissions are, so to speak, at cross purposes, such that a substantial overall transmission loss for the high frequencies is achieved. Also, the bond of the layer 88 to the layer 87, which is in turn bonded to the wall 48, results in additional damping of vibration of wall 48, since such vibration must vibrate the fibrous absorptive material of layer 88, and thus further dissipate sonic energy.

The still higher frequency sound, such as above 8,000 cycles, is managed by the perforated metal wall 89. Incident sound waves are capable of easily traveling through the multiplicity of small perforations in the Wall 89, but in so doing, they are broken or transformed into different wave trains of different frequencies Whose energy is readily dissipated within the absorptive layer 88. Thus, the perforated sheet 89 reduces the amplitude of sound in the range upwards of 8,000 cycles or thereabout.

FIG. 8 shows a performance graph of an actual com mercial panel constructed generally according to FIG. 4. Noise reduction up to 10,000 cycles Will be seen to be very good, with superior performance in the low frequency range. The coefficient of absorption at 256 cycles is .97, and at 128 cycles is .60, which are high for these frequencies, as will be recognized by those skilled in the art.

Reference is next'directed to FIG. 5, which discloses an acoustic panel 91 which may be substantially identical to that of FIG. 4, with the sole significant difference that it uses for its front, acoustically transparent sheet or layer a thin plastic film 92 in place of the perforated wall 89. Thus, the panel 91 has a metal pan 46 as before, with an outside wall 48, a layer 87 of dense material bonded to wall 48, and a layer 88 of acoustic absorptive material, of lesser density, as rock Wool, fiberglass or the like, bonded to dense layer 87. Over and bonded to the layer 88 in FIG. 5, and joined to the flanges 50, is a thin flexible plastic film 92. This film 92 may be perforated, or imperforate, and certain advantages are gained from the imperforate film.

The panel 51 of FIG. functions as does that of FIG. 4, excepting for certain differences resulting from the use of the plastic film. Assuming first an imperforate flexible plastic film 92, the film vibrates readily with incident sound, excepting in the higher frequency ranges, so as to transmit the sound into the absorptive layer 88, after which it is attenuated as in the panel of FIG. 4. As the higher frequencies are approached, the film tends more and more to act as a reflective barrier, and to reflect the sound back, and is effective above approximately 8,000 cycles per second to prevent large transmissions of sound into the layer 88. Being bonded to the layer 88, the tendency of the film 92 to vibrate with incident sound is, of course, transmissive of sound vibrations into the absorptive layer 88, where they are largely dissipated, if in the range of approximately 200 to 8,000 cycles, or dissipated by the dense layer 87 bonded to the metal back wall 48 of the pan if in the lower frequencies. It will be further seen that both the absorptive layer 88 and the film 92 bonded thereto have a dampening eflect on the metal wall 48. In the event of use of a perforate film 92, bonded to the layer 88, the sound waves can enter both by vibrating the film and by passing through the perforations. Transmission through the perforations has substantially the same attenuative or dissipative effect as in the case of the perforate metal 89 of FIG. 4.

I may also use a combination of the structures of FIGS. 4 and 5, with a thin plastic film of FIG. 5 between the fibrous absorptive layer 88 and the perforated metal plate 89 of FIG. 4, with the film preferably bonded to the fibrous layer 88, and bonded also, if desired, to the perforate metal plate. The remainder of the structure may be as in FIGS. 4 and 5. This combination, for reasons not yet determined, has shown an enhanced attenuation for the lower frequencies.

Finally, FIG. 7 shows an improved heavy form of the invention which I have developed, and which is useful for high attenuation throughout an extended frequency range. In this case, a metal pan 46 is used as before, with a wall 48, and other structural arrangements as described in connection with FIGS. 4-6. The wall 48 is preferably 18 gauge sheet steel. Bonded to this wall 48 is a hard and dense layer 87, composed of a material such as plasterboard or Masonite, of a thickness of one-half to one inch. Next to and bonded to this dense layer 87 is a typically two to three inch thick layer 88 of porous sound absorptive material, such as rock wool or the like, preferably of fairly heavy density for rock wool. Over and bonded to the heavy density layer 88 of porous material is a lighter density layer 95, composed of fiberglass or the like, and typically of one-half inch in thickness. Over and either bonded or not bonded to the layer is a perforated sheet metal front layer or wall 89. The walls and layers 48, 87, 88 and 89 serve generally purposes and functions which are equivalent to those of the corresponding members in the panel of FIG. 4. The extra lighter density porous layer 95 acts as an absorptive layer for frequencies in a higher range than the layer 88, being effective in the approximate range of 6,000 to 12,000 cycles, per second. The perforated steel outer layer 89 is preferred, but it will be understood that a flexible plastic sheet, like that of FIG. 5, perforate or imperforate, may be used in place of the perforated steel layer 89 if desired. Such a flexible plastic sheet, if used, will be bonded to the layer 95.

All of the several prefabricated, modular panel structures of FIGS. 4-7 are designed for assembly in precisely the same Way described earlier with respect to the panel units of FIG. 1. Clearly, therefore, any one of these panel constructions can be used in the prefabricated modular panel building structure of FIG. 1 to make a thermally or acoustically insulated room or a dust-free room. The various panels can be provided with a door, window, ventilation conduit, or service connections in the same manner as discussed earlier with reference to FIG. 1.

Clearly, therefore, the invention is fully capable of attaining the objects and advantages preliminarily set forth.

Numerous modifications in the design, arrangement of parts, and instrumentalities of the invention are, of course, possible Within the spirit and scope of the following claims.

I claim:

1. A prefabricated soundproof enclosure panel, comprising:

a sheet metal outside wall;

a solid sheet of dense acoustic insulation material, of substantially greater thickness than said sheet metal wall, forming a substantially reflective barrier wall to low frequency sound bonded face-to-face to the inside surface of said sheet metal wall;

a layer of fibrous and porous acoustic absorptive material adjacent and bonded to said solid sheet, said layer being of substantially greater thickness than said solid sheet of dense material; and

an acoustically transparent sheet in front of said layer of fibrous and porous material.

2. The subject matter of claim 1, including also a layer of fibrous and porous acoustic absorption material, between said first mentioned layer of porous absorption material and saidacoustically transparent sheet and bonded to said first mentioned layer, and composed of material of lesser density than said first mentioned layer of porous absorptive material.

3. The subject matter of claim 1, wherein said acoustically transparent sheet comprises a sheet metal wall formed with a multiplicity of small perforations.

4. The subject matter of claim 3, including also a flexible film between the perforated sheet metal wall and said layer of fibrous and porous acoustic absorptive material.

5. The subject matter of claim 1, wherein said acous- 2,177,393 10/1939 Parkinson 52-145 tically transparent sheet comprises a relatively thin flexible 2,933,147 4/ 1960 Stewart et al 181--33.1 film bonded to said layer of porous absorptive material. 2,981,360 4/1961 Rim; 1 181-331 6. The subject matter of claim 5, where n said flel db e 3,021,914 2/1962 Wilson 181-33.1 film is formed wlth a rnultlplicity of small perforations. 5 FOREIGN PATENTS References Ci ed 994,491 11/ 1951 France.

UNITED STATES PATENTS 1,900,522 3/1933 Sabine 181-3311 FRANK T pr'mary xamme" 1,976,282 10/1934 Izumiyama 1s1 33.1 R- S. VERM T, n 

1. A PREFABRICATED SOUNDPROOF ENCLOSURE PANEL, COMPRISING: A SHEET METAL OUTSIDE WALL; A SOLID SHEET OF DENSE ACOUSTIC INSULATION MATERIAL, OF SUBSTANTIALLY GREATER THICKNESS THAN SAID SHEET METAL WALL, FORMING A SUBSTANTIALLY REFECTIVE BARRIER WALL TO LOW FREQUENCY SOUND BOUND FACE-TO-FACE TO THE INSIDE SURFACE OF SAID SHEET METAL WALL; A LAYER OF FIBROUS AND POROUS ACOUSTIC ABSORPTIVE MATERIAL ADJACENT AND BOUNDED TO SAID SOLID SHEET, SAID LAYER BEING OF SUBSTANTIALLY GREATER THICKNESS THAN SAID SOLID SHEET OF DENSE MATERIAL; AND AN ACOUSTICALLY TRANSPARENT SHEET IN FRONT OF SAID LAYER OF FIBROUS AND POROUS MATERIAL. 